The preparation and some reactions of cyclopropyldiazomethane and cyclopropylmethyldiazotate

The Fragmentation of Alkoxyhalocarbenes

“…2 Thus, the reactions (in ether) of cyclopropyldiazomethane with benzoic acid, or of cyclopropylmethyl diazotate with benzoyl chloride, afford cyclopropylmethyl benzoate ion pairs 13, which yield the benzoate analogues of 10-12 in distributions very similar (79:14:7 or 78:13:9) to those of the cyclopropylmethyl cation-carbon monoxide-chloride ion pair of eq 6. 17 When the fragmentation of 9 occurs in ethanol, we obtain 49% of chlorides 10-12 with a high 10/11 distribution (8.4), as well as 51% of the ethyl ether analogues of 10-12 with a much reduced cyclopropylcarbinyl/cyclo- butyl distribution (1.3). The chloride products represent ion pair return (probably from a "cis" ion pair analogous to 8), whereas the ether products most likely derive from solvolysis of a "trans" ion pair, or an ethanol-solvated (escaped) cyclopropylmethyl cation; the cyclopropylcarbinyl/cyclobutyl ratio is now very similar to the distribution obtained from the "free" cyclopropylmethyl cations formed in the nitrous acid deamination of cyclopropylmethylamine 14,16 or the hydrolysis of cyclopropylmethyl diazotate.…”

“…The case for ion pair intervention in eq 6 is strengthened if we recall Skell's analogy to the chemistry of alkyldiazonium ions . Thus, the reactions (in ether) of cyclopropyldiazomethane with benzoic acid, or of cyclopropylmethyl diazotate with benzoyl chloride, afford cyclopropylmethyl benzoate ion pairs 13 , which yield the benzoate analogues of 10 − 12 in distributions very similar (79:14:7 or 78:13:9) to those of the cyclopropylmethyl cation−carbon monoxide−chloride ion pair of eq 6 …”

Synthesis of 2-substituted bicyclo[2.1.0]pentanes from bicyclo[3.1.0]hexan-2-one

“…(b) Hydrogen peroxide (90%; 1.5 g, 0.04 mol) was added dropwise to stirred trifluoroacetic anhydride (10.6 g, 0.05 mol) at 0 °C during 15 min. When homogeneous, the mixture was taken up in dichloromethane and the solution was added dropwise during 15 min to a well stirred mixture of dry, finely divided disodium hydrogen phosphate (14.2 g, 0.10 mol), a mixture of epimeric 2-acetylbicyclopentanes (12) (1.6 g, 0.01 5 mol), and dichloromethane (16 ml). The reaction mixture was heated under reflux for 2 h, after which the suspension was filtered and washed with dichloromethane.…”

The chemistry of nitrosoamides

“…With the proper choice of conditions, base catalyzed decompositions of nitrosoamides can bo adapted to the study of alkyl deaminations (77). In an interesting scries of experiments, Moss and co-workers (17)(18)(19)(20) studied the stereochemical return and solvolysis pathways [eqn. (8)]…”